#include "log.h"
#include <stdbool.h>

#define MAX_CALLBACKS 32

typedef struct {
	log_LogFn fn;
	void     *udata;
	int       level;
} Callback;

static struct {
	void      *udata;
	log_LockFn lock;
	int        level;
	char       quiet;
	Callback   callbacks[MAX_CALLBACKS];
} L;

static const char *level_strings[] = {"DBG", "INF", "WRN", "ERR", "FTL"};
// static const char *level_strings[] = {"DEBUG", "INFO", "WARN", "ERROR", "FATAL"};

static void stdout_callback(log_Event *ev) {
	char buf[16];
	buf[strftime(buf, sizeof(buf), "%m-%d %H:%M:%S", ev->time)] = '\0';
#ifdef LOG_COLOR
	static const char *level_colors[] = {"\x1b[32m", "\x1b[36m", "\x1b[33m", "\x1b[31m", "\x1b[35m"};
	fprintf(ev->udata, "%s %s%-3s \x1b[0m\x1b[90m\x1b[0m", buf, level_colors[ev->level], level_strings[ev->level]);
	// fprintf(ev->udata, "%s %s%-5s\x1b[0m \x1b[90m%s:%d:\x1b[0m ", buf, level_colors[ev->level], level_strings[ev->level], ev->file, ev->line);
#else
	fprintf(ev->udata, "%s %-5s %s:%d: ", buf, level_strings[ev->level], ev->file, ev->line);
#endif

	vfprintf(ev->udata, ev->fmt, ev->ap);
	fprintf(ev->udata, "\n");
	fflush(ev->udata);
}

static void file_callback(log_Event *ev) {
	char buf[64];
	buf[strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", ev->time)] = '\0';
	fprintf(ev->udata, "%s %-5s %s:%d: ", buf, level_strings[ev->level], ev->file, ev->line);
	vfprintf(ev->udata, ev->fmt, ev->ap);
	fprintf(ev->udata, "\n");
	fflush(ev->udata);
}

static void lock(void) {
	if (L.lock) {
		L.lock(1, L.udata);
	}
}

static void unlock(void) {
	if (L.lock) {
		L.lock(false, L.udata);
	}
}

const char *log_level_string(int level) { return level_strings[level]; }

void log_set_lock(log_LockFn fn, void *udata) {
	L.lock  = fn;
	L.udata = udata;
}

void log_set_level(int level) { L.level = level; }

void log_set_quiet(char enable) { L.quiet = enable; }

int log_add_callback(log_LogFn fn, void *udata, int level) {
	for (int i = 0; i < MAX_CALLBACKS; i++) {
		if (!L.callbacks[i].fn) {
			L.callbacks[i] = (Callback) {fn, udata, level};
			return 0;
		}
	}
	return -1;
}

int log_add_fp(FILE *fp, int level) { return log_add_callback(file_callback, fp, level); }

static void init_event(log_Event *ev, void *udata) {
	if (!ev->time) {
		time_t t = time(NULL);
		ev->time = localtime(&t);
	}
	ev->udata = udata;
}

void log_log(int level, const char *file, int line, const char *fmt, ...) {
	log_Event ev = {.fmt = fmt, .file = file, .line = line, .level = level};
	lock();
	if (!L.quiet && level >= L.level) {
		init_event(&ev, stderr);
		va_start(ev.ap, fmt);
		stdout_callback(&ev);
		va_end(ev.ap);
	}

	for (int i = 0; i < MAX_CALLBACKS && L.callbacks[i].fn; i++) {
		Callback *cb = &L.callbacks[i];
		if (level >= cb->level) {
			init_event(&ev, cb->udata);
			va_start(ev.ap, fmt);
			cb->fn(&ev);
			va_end(ev.ap);
		}
	}
	unlock();
}
